This invention relates to an optical disc drive and a computer system including an optical disc drive, and more particularly, to a control technology for recovering from a standby state to an active state on an optical disc drive for achieving power savings by shifting to the standby state or a hibernate state.
In recent years, demand has grown for computer systems having reduced power consumption as well as improved processing capabilities. Therefore, a power saving technology as disclosed in JP 2007-164915 A is known for an optical disc drive. In the power saving technology, the optical disc drive is caused to shift to a hibernate state (suspend state or power saving state) such as a sleep state during a period during which no access is made from a host computer.
Upon reception of a write command or a read command from the host computer in the hibernate state, the optical disc drive causes a stopped optical disc to rotate and starts a processing corresponding to the received command after a predetermined rotational speed is reached. Here, on the optical disc drive, a rotational speed of the stopped optical disc is raised to a predetermined rotational speed and a writing test or other such processing is performed to thereby cause a delay until the writing or the reading is started. A delay time that passes until the optical disc drive recovers from the hibernate state may cause a time-out in an OS or the like running on the host computer.
JP 2009-3831 A discloses a technology as an example of a technology as described above for preventing the time-out on the host computer accompanied by the recovery from the hibernate state. In the technology, a time-out period is set in advance for each host computer, and during the recovery from the hibernate state, the rotational speed of the optical disc is changed so that the processing corresponding to the command from the host computer can be started within the time-out period.